1. Field of the Invention
The present invention broadly concerns barrel-type milking claws of the type having a window to permit visual inspection of the interior of the claw, and more particularly to a milking claw having a concave window. In addition, the invention concerns a barrel-type milking claw having a window which is provided with a relief section, either raised or indented, to facilitate gripping by a user.
2. Description of the Prior Art
In a milking parlor for dairy animals, such as goats or cows, automated milking is typically accomplished by teat cups which are attached to the teats of the animal and then lead to a milking claw. The milking claw thus collects the milk obtained from the animal and delivers it downstream to a weighing device, flow meter, and/or bulk milk tank. Typically, by the periodic and alternate application of vacuum and atmospheric pressure to the teat cup, the milk is extracted from the udder and delivered to the milking claw. One type of milking claw which has long been used, and is preferred by many dairymen, is known as a barrel-type claw.
The barrel-type claw is typically provided with a cylindrical central body which is of sturdy construction, such as stainless steel which may be readily cleaned, a plurality of nipples fluidically connecting the teat cups to the body, a spout for discharging milk to a milking hose for delivery downstream, and windows which are sealingly attached to each end of the body to permit viewing of the interior of the claw. Barrel claws have enjoyed popularity because they are sturdy and not easily damaged, and fit comfortably into the hand of the operator. However, notwithstanding the foregoing general advantages, the windows of prior art barrel claws are broken due to impact, such as by the hoof of a cow or by dropping on the hard parlor floor, and the when held, milk, water, or other material deposited on the surface of the claw may cause the grip on the claw to slip. In addition, the introduction of warm milk from the udder or a hot water cleaning solution into a relatively cold milking claw where the window is of a different material (e.g. glass or more typically plastic) than the body may cause thermal stresses on the sealing relationship between the window and the body.
The milking claw of the present invention has been designed with these concerns in mind. While retaining the advantages of a barrel claw configuration, the milking claw hereof provides enhanced protection of the windows of the claw and improved gripping by the user. In addition, by providing a window of a concave configuration, not only is the protection of the window enhanced, but the ability of the window to avoid stress concentration around the perimeter during thermal expansion avoided. Additionally, the barrel claw of the present invention benefits from the provision of a gasket which substantially completely surrounds the window, thereby providing improved sealing and cushioning both for impact but also for thermal expansion.
In this regard, the milking claw of the present invention retains the benefit of the generally barrel-shaped body, which may include not only a cylindrical body but also a body with tapered end portions to improve volumetric capacity in the center but retain the ergonomic benefits of smaller conical end portions, but additionally includes windows presenting a concave outer surface so that the surface remains recessed relative to the longitudinally outer margins of the body. The concave surface of the window is thereby protected from impact, and further provides increased flexibility over flat surfaces. This in turn permits the window to flex and absorb stress caused by occasions where thermal expansion of the body will be different than the window. Instead of concentrating the stress around the perimeter occasioned by a flat window surface, the arcuate surface of the window permits the window to more readily flex and enables the window to distribute the stress more fully throughout the window.
The window may be provided with a relief in its surface, such as by a raised area or an indented area. Such a raised or indented area provides improved gripping for the dairyman, without detracting from the overall ability to view through the window. By providing an relief in the window, the dairyman may grasp the generally arcuate claw but have improved gripping on the surface by having an edge or the like on the otherwise smooth surface and gives a purchase to prevent slippage from the dairyman""s hand.
These and other important objects will be made clear from the description and claims which follow: